Significance Although viruses which are a combination of SIV and HIV (SHIV) and do not cause disease in monkeys are potent vaccines capable of protecting against SIV challenge, the are potential virulent and a molecular clone or DNA from a clone has the potential to be much safer. Objectives The present study was designed to determine if a virus stock grown from a molecular clone isolated from SHIV89.6PD.was pathogenic and if the DNA from that clone could be infectious. Results Two rhesus macaques were inoculated intravenously with a virus stock generated from the molecular clone. Both animals are infected but healthy at 13 months PI. Two animals were inoculated intramuscularly with the DNA use to generate the stock but neither animal became infected. Future Directions Because naked DNA may be the best way to deliver attenuated virus vaccines, we will attempt to produce an infectious DNA plasmid using alternate strategies. KEYWORDS SHIVvirulence, viral pathogenesis, SHIV molecular clone and DNA